CN102931023A - Realization of control method and device for vacuum circuit breaker based on coil current - Google Patents
Realization of control method and device for vacuum circuit breaker based on coil current Download PDFInfo
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- CN102931023A CN102931023A CN2012104619134A CN201210461913A CN102931023A CN 102931023 A CN102931023 A CN 102931023A CN 2012104619134 A CN2012104619134 A CN 2012104619134A CN 201210461913 A CN201210461913 A CN 201210461913A CN 102931023 A CN102931023 A CN 102931023A
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Abstract
The invention provides a control method and a control device for a permanent magnet vacuum circuit breaker. The control method comprises the following steps: measuring coil current of a permanent magnet mechanism; and acquiring a reference current curve for controlling in real time, as well as a hysteresis control algorithm unit. The control method is characterized in that any part is not required to be additionally arranged on a circuit breaker body; the current of a coil is measured in real time and is compared with reference current and an actual trigger signal of a power device is determined by a hysteresis control algorithm, so that the real-time closed loop control over the coil current is realized and further the switch-on-off time of the permanent magnet vacuum circuit breaker is kept consistent; and the realization of corresponding device is designed according to the method. Proved by actual experiments, the control method has the characteristics that the dispersibility of the switch-on-off time of the vacuum circuit breaker is effectively reduced and the dynamic error range of the switch-on-off of the vacuum circuit breaker is maintained at +/-0.3ms.
Description
Technical field
The present invention relates to the control technology field of vacuum circuit breaker permanent-magnet operating mechanism, particularly relate to a kind of control device for vacuum circuit breaker and control method based on permanent magnet mechanism coil current curve.
Background technology
The control method of current circuit breaker mostly is open-loop control method, and namely circuit breaker is in the breaking-closing operating process of reality, and the divide-shut brake order that receiving control device sends triggers corresponding IO and finishes order, shown in Figure 1A.The contact state of the uncontrollable circuit breaker of this method, be in open position at higher operating voltage and contact and carry out sub-switching operation and contact and be in closing position and carry out in the situation of closing operation, easily because of by the excessive coil burnout that causes permanent magnet mechanism of the electric current of coil.Because the contact action process is not controlled, electrical quantity variation that easily is subjected to energy storage capacitor capacity, operating voltage the operate time of circuit breaker and causes because of factors such as working temperatures etc. affects, make larger variation occur the operate time of circuit breaker, be unfavorable for circuit breaker is realized Synchronization Control.Realize that under higher operation voltage breaking-closing operating can make movement velocity unshakable in one's determination increase, thereby make contact bear larger impulsive force, reduce mechanism useful life, and may make moving contact that repeatedly spring occurs, impact is closed and is closed reliability.When moving contact speed was larger, the energy loss that causes was also more, was unfavorable for the realization of circuit breaker multiple shot reclosing.
The another kind of control method of current circuit breaker is based on the closed loop control method of moving contact of breaker displacement curve, as shown in Figure 1B.Though this method can be controlled the stroke of moving contact, still since displacement transducer in the course of the work its internal measurement tap be kept in motion, self easily breaks down, and measures number of times limited.In addition, displacement transducer need to directly be connected with the moving contact connecting rod usually, is difficult for installing, and also easily brings out electric fault.The closed loop control method that uses displacement transducer because of these drawbacks limit of unique transducer its application.
Therefore need to provide a kind of can improve circuit breaker work consistency, job stability and reliability, effective control device of prolongation breaker mechanical life-span and control method.
Summary of the invention
In order to address the above problem, the invention provides a kind of vacuum circuit-breaker control method based on permanent magnet mechanism coil current curve and device realization.
The invention provides a kind of control method of permanent magnetic vacuum breaker, the method comprises the coil current of measuring permanent magnet mechanism, obtains the reference current curve of controlling in real time, and the ring control algolithm unit that stagnates,
It is characterized in that need not increasing any parts at breaker body, electric current by real-time measuring coil and with the contrast of reference current, determined the actual triggering signal of power device by the ring control algolithm that stagnates, realization is to the real-time closed-loop control of coil current, thereby the branch wire time of permanent magnetic vacuum breaker is consistent
The method further comprises:
Be used for obtaining the method for reference current curve,
4 medium filterings of windowing that are used for the signal Real-Time Filtering,
Follow-on stagnant ring control algolithm unit.
Preferably, the method comprises 4 medium filterings with the rectangular window translation, is used for the real-time sampling current signal is carried out filtering, to satisfy real-time control algolithm to the requirement of input signal.
Preferably, using modified hysteresis control method thereof calculates real-time current value and reference current value difference, and further converts the pwm signal of driving power device to, realizes the tracking control to coil current.
Preferably, the acquisition methods of Coilreference current curve, the method includes the steps of:
A. be identified for obtaining capacitance and the magnitude of voltage of reference curve, for the circuit breaker of same model, this step only need be carried out once, wherein comprises following content:
Determine that according to the parameter of known circuit breaker model normal execution is once closed a floodgate or capability value and the initial voltage of the minimum energy storage capacitor that separating brake is required;
In the situation that hardware condition allows, use the principle of capacitance energy storage equivalent, the capacitance energy storage formula
Improve the voltage of electric capacity as far as possible and reduce the capacity of electric capacity, reducing divide-shut brake in the time of the whole time, the end speed of restriction divide-shut brake reaches the purpose of protection moving contact.Repeatedly test to obtain best vacuum circuit-breaker displacement curve, be identified for obtaining capacitance and the electric capacity initial voltage value of this model circuit breaker reference current curve, this step is used for optimizing reference curve, in not permission of hardware condition situation, can omit;
B. before a certain circuit breaker of described model comes into operation, the capacitance and the magnitude of voltage that utilize A to determine, carry out respectively separating brake and closing operation, by control device self sampling and record the divide-shut brake current curve of this operation as the reference curve of the normal separating brake of this circuit breaker and closing operation.
Preferably, choose the capacitance when being higher than determined capacitance be used to obtaining reference curve as normal breaking-closing operating, and choose the magnitude of voltage that is higher than be used to the normal breaking-closing operating of magnitude of voltage conduct that obtains reference curve, the capacitance energy storage during with the assurance normal running satisfies the needs of reclosing.
The present invention further provides a kind of control device of permanent magnetic vacuum breaker, this application of installation preceding method principle design, it comprises the control unit that discharges and recharges of electric capacity, IGBT power stage unit, current measuring unit, and control core unit, wherein
This capacitor charging/discharging control unit is used for according to the signal that discharges and recharges from the control core unit energy storage capacitor of control device being discharged and recharged,
This IGBT power stage unit is used for according to exporting the discharging current of energy storage capacitor to coil from the triggering signal of control core unit,
This current measuring unit is measured the coil current of described IGBT power stage unit output and is fed back to the control core unit,
This control core unit utilizes follow-on stagnant ring control algolithm to be identified for the triggering signal of IGBT power stage unit based on the coil current of measuring and the contrast of reference current, and the branch wire time of permanent magnetic vacuum breaker is consistent.
Preferably, this control core unit further comprises filter unit, is used for from the feedback current of described current measuring unit 4 medium filterings with the rectangular window translation.
Preferably, this control core unit comprises that based on the stagnant control unit that encircles, this stagnates and encircles control unit based on the deviation of described feedback signal and described reference current, and the stagnant chain rate of foundation is than the control of algorithm realization to IGBT power stage unit.
Preferably, this control device comprises the energy storage capacitor that the parameter value of the breaker permanent magnet control mechanism that comprises that further its capacitance is controlled according to control device is selected.
Preferably, this control device comprises that further the capacitance of its normal use should be less than the energy storage capacitor for the condenser capacitance value of obtaining the reference coil current curve.
Preferably, this control device further comprises memory, and each that is used for that storage controls respectively each phase coil of permanent-magnet manipulating mechanism be with reference to the coil current curve,
Current measuring unit is measured respectively each phase coil current output of IGBT power stage unit output,
This control core unit is based on each phase reference current of storage with from each phase feedback signal of described current sensor, use the actual triggering signal that the ring algorithm that stagnates calculates IGBT, so that each phase coil current of described IGBT power stage unit output is consistent with reference to the coil current curve respectively with each.
Preferably, described current measuring unit is Hall current sensor.
The present invention is based on the control method of permanent magnet mechanism dynamic characteristic, by improving the chain rate that stagnates than algorithm, control permanent magnet mechanism coil current is pressed the output of reference current curve, make permanent magnetic vacuum breaker moving contact stroke be in slave mode, thereby make the time of the each time breaking-closing operating of circuit breaker remain certain value.The kinetic characteristic each owing to circuit breaker is consistent, can be according to the selected dynamic characteristic of circuit breaker, can know the contact displacement curve and know corresponding contact travel by the coil current curve that measures, realize the noncontact static measurement to the breaker permanent magnet control mechanism contact.Can be independent of circuit breaker to the measurement of circuit breaker carries out.The feedback system of this measurement and measuring-signal compared with prior art, measurement mechanism is easily installed, Measurement sensibility is good, and easy to operate, has significantly improved the difficult installation that existing measurement mechanism exists and the defective that easily breaks down.By utilizing the electric current of the current sensor feed sensing control device output in the control device, make the electric current whole process of drive coil controlled, thereby effectively avoided the possibility of coil burnout.By choosing appropriate coil current performance graph, can reduce moving contact and reach the limit of the suffered impulsive force in position, the protection moving contact also weakens contact bounce, and then improves the reliability of mechanism action, extending mechanism useful life.Employing is according to control device of the present invention and control method, can effectively reduce electric parameter changes such as coil resistance rate because of energy storage capacitor capacitance and permanent-magnet manipulating mechanism etc. to the impact of circuit breaker running parameter, make the breaking-closing operating time of circuit breaker remain certain value, make based on the circuit breaker of permanent magnet mechanism can realize reliably Synchronous Closing, and have good consistency.In addition, by promoting divide-shut brake voltage, and choose suitable Current Control curve, can reduce branch wire time, reduce contact because of the energy loss that collision causes, reach energy-conservation effect, make circuit breaker under the condition of identical use, can finish more frequently reclosing operation, effectively prolong the useful life of circuit breaker, improve simultaneously the stability of electric power system.
Description of drawings
Fig. 1 (a) and 1(b) schematically show the block diagram of the breaker permanent magnet control mechanism controller of prior art;
Fig. 2 schematically shows the structured flowchart of breaker permanent magnet control mechanism;
Fig. 3 schematically shows the combined floodgate dynamic characteristic of the permanent magnet mechanism under the open loop situations.
Fig. 4 schematically shows the structured flowchart of the breaker permanent magnet control mechanism control device according to the present invention;
Fig. 5 illustrates the current curve that current sensor measurement obtains;
Fig. 6 illustrates the current curve before and after the filtering;
Fig. 7 schematically shows the method according to definite reference coil current curve of the present invention;
Fig. 8 schematically shows the control method according to breaker permanent magnet control mechanism of the present invention;
Fig. 9 and Figure 10 illustrate respectively the circuit breaker open loop performance graph of the example 1 according to the present invention;
Figure 11 and Figure 12 illustrate respectively coil current curve comparison and the displacement curve contrast of the example 2 according to the present invention;
Figure 13 and Figure 14 illustrate respectively coil current curve comparison and the displacement curve contrast of example 3;
Figure 15 and Figure 16 illustrate respectively coil current curve comparison and the displacement curve contrast of example 4;
Figure 17 and Figure 18 illustrate respectively the breaker closing position of example 5 and the coil current curve of open position.
Embodiment
Below with reference to accompanying drawings and in conjunction with the preferred embodiments of the present invention the solution of the present invention is described in detail.It is clear and for simplicity to should be appreciated that as making, and well known to a person skilled in the art that the connected mode of some parts in the permanent-magnet manipulating mechanism and operation principle will repeat no more here.
Fig. 2 schematically shows the structured flowchart of Monostable permanent magnetism operating mechanism.This permanent-magnet manipulating mechanism comprises moving iron core 1, fixed core 2, divide-shut brake coil 3, permanent magnet 4, non-magnetic cover plate 5, air-gap 6, and tripping spring 7.Mechanism shown in Figure 2 is in gate-dividing state, by the control device of permanent-magnet manipulating mechanism, to divide-shut brake coil 3 triggering of charging.The electromagnetic force that produces at moving place unshakable in one's determination when the magnetic field that the divide-shut brake coil produces is during greater than the spring tension of separating brake 7, and moving unshakable in one's determination 2 begin action, and feed motion begins.When adopting control device shown in Figure 4 that permanent-magnet manipulating mechanism is controlled, the moving equation of motion unshakable in one's determination can be provided by following equation 1.
Equation 1
In the formula, U
cBe energy storage capacitor both end voltage in the control device; I, Ψ are respectively divide-shut brake coil current and electromagnetic system total flux linkage; T is the time; X is moving displacement with respect to open position unshakable in one's determination; M is that the reduction of electromagnetic system moving component is to the quality at moving place unshakable in one's determination; F
Mag, F
fBe respectively electromagnetic attraction and motion counter-force that moving iron core is subject to; W
μBeing the magnetic energy of electromagnetic system, is i, the function of Ψ; C is the capacity of energy storage capacitor, electromagnetism gap, δ position.
Be the above-mentioned equation group of direct solution, need the relation of known permanent-magnet operating mechanism for circuit breaker electromagnetic force, the resistance of motion and displacement etc.Under the given parameters condition, by analyzing and ignore the impact of some secondary cause, can obtain the theoretic trend of coil current curve.Because operating mechanism self parameter differences, the many factors such as sensor measurement performance difference and actual operating condition, coil actual current curve usually and theoretical curve larger deviation is arranged.This deviation may cause the control mistake of control device, and causes thus the misoperation of circuit breaker.
Occur for fear of this problem, wish that control device controls breaker coil according to the reference coil current curve with desirable control effect.
As shown in Figure 4, the control device of vacuum circuit breaker permanent-magnet operating mechanism of the present invention comprises the control core unit, memory cell, capacitor charging/discharging control unit, IGBT power stage unit, current measuring unit.Type and the parameter of the vacuum circuit-breaker that can control according to control device are selected suitable energy storage capacitor, the energy storage capacitor that is connected with the capacitor charging/discharging control unit carries out charging and discharging according to the signal that discharges and recharges from the capacitor charging/discharging control unit, makes the voltage of energy storage capacitor can satisfy the requirement that the operating breaker permanent-magnet manipulating mechanism carries out breaking-closing operating.Memory cell is used for stored reference coil current curve.IGBT power stage unit has output port, and the energy that IGBT power stage unit is stored energy storage capacitor based on the triggering signal of control core unit output exports the permanent-magnet manipulating mechanism coil to by output port.Current measuring unit, preferred Hall current sensor, when being used for measuring the circuit-breaker switching on-off operation by described permanent-magnet manipulating mechanism coil current, the electric current of namely sensing IGBT output port output, and with the current feedback that measures to the control core unit.The control core unit is based on the reference coil electric current of reference coil current curve and comparison from the feedback signal of described current sensor, and the output triggering signal is so that coil current and the reference current of the output of IGBT power stage unit are consistent.This control device can further comprise filter, is used for the feedback signal from current sensor is carried out filtering.More preferably, the control core unit of this control device comprises filter unit, and the ring control unit that stagnates.The ring control unit that stagnates calculates the triggering signal of output IGBT than algorithm according to the chain rate that stagnates based on the deviation of described feedback signal and described reference current.According to the type of circuit breaker, control device can have many group IGBT output ports, to realize each the mutually discrete control to the discrete control formula of three-phase circuit breaker.In the case, the current measuring unit of respective numbers is measured respectively the three-phase coil electric current of IGBT output port output and is fed back to the control core unit.Three phase feedback signals that the control core unit will receive respectively with memory in the three-phase reference coil current curve separately stored compare, and IGBT power stage unit controlled, so that coil current and each phase coil current curve of each phase output terminal mouth output of IGBT are consistent.
Control device can be under open loop situations, and for the capacitor and different initial voltages of one group of different capacitance, sampling obtains one group of divide-shut brake dynamic characteristic that comprises at least coil manipulation current curve and contact displacement curve.For example Fig. 3 schematically shows breaker closing dynamic characteristic under the open loop situations, shows the relation between coil current and the displacement curve, and ordinate is electric current/displacement measurement, and abscissa is the time.In the memory cell that the coil current curve of selecting to make circuit breaker have desirable operating characteristics in a resulting suite line is kept at as reference coil current curve.Selection has the capacitor of capacitance corresponding to this reference coil current curve and initial voltage as the energy storage capacitor that is applied to this circuit breaker, and according to this reference curve energy storage capacitor and IGBT power control unit are controlled, make the electric current output consistent with the reference coil current curve of this control device.
Preferably, control unit of the present invention further comprises for to the described filter unit that carries out filtering from the feedback signal of described current sensor, for example carries out 4 medium filterings of windowing.
Because the impact of power supply and electromagnetic environment of living in comprises a large amount of noise jamming in the current signal that current sensor obtains.Fig. 5 has provided when capacitance is 4700 μ F, wherein one makes up brake cable loop current curve to what the discrete control formula of three-phase 12kV circuit breaker obtained.There are a large amount of burrs in current curve data shown in Figure 5, can't be directly used in real-time control.So need a kind of effective filtering algorithm, realize fast the filtering to current curve, and filtered data are used for stagnant ring algorithm, so that in real time control coil electric current output.Because the breaking-closing operating time of circuit breaker is of short duration, for avoiding larger filtering delay-time occurring with real-time reflection coil current value, has taked 4 medium filterings of windowing.This algorithm is as follows:
Filter unit adopts this algorithm to carry out current signal filtering, has guaranteed the delivery efficiency of data, has reduced the requirement to the A/D sampling rate.In the reality of industrial control field, when the A/D sampler less than 16, when using 32 bit CPU based on the ARM core, 16 exchanges of height that can take full advantage of 32 bit data realize filtering rapidly.Be determined at down through real-time simulation, work under the LPC2292 of 60MHz, the data output delay time of filter unit is less than 360ns.Fig. 6 has provided the contrast of filtering front and back current curves.As seen in Figure 6, adopt filter unit according to the present invention that current signal is carried out filtering, filtered data and curves is comparatively level and smooth, can satisfy the needs of real-time control.
In the closed-loop control situation of control device, stagnate the ring control unit with reference to current curve as command signal, from the current signal of Hall element as feedback signal, calculate both transient deviations, and according to the triggering signal of this deviation output control IGBT power stage unit, so that the electric current of flowing through coil and reference current curve are consistent.
Specifically describe the method step that obtains the reference coil current curve below in conjunction with Fig. 7.
Breaker operating characteristic is in the ideal case, and circuit-breaker switching on-off speed raise rapidly in the incipient stage, and interlude is kept high-speed motion, to reduce the overall time of divide-shut brake; Before arriving the pass chalaza, underspeed to reduce the energy of moving contact collision, and remain on the Synchronization Control requirement that drops into synchronously electric power system in the certain speed range to satisfy electric equipment.
From above-mentioned operating characteristics as can be known, for obtaining desirable curve, at first should be identified for according to the parameter of known type circuit breaker capacity and the initial voltage of one group of energy storage capacitor of definite reference curve, step S701.
Actual parameter according to the type circuit breaker that will control, take operating time of reducing divide-shut brake and reduce to arrive close chalaza speed as principle, determine energy storage capacitor needed position of minimum capacitance when satisfying a separating brake or closing a floodgate by above-mentioned dynamic equation 1.The principle that can roughly equate according to capacitive energy is determined capacitance and initial voltage value.When choosing high voltage, capacitance that can corresponding minimizing capacitor.Be to be understood that, the raising of the initial voltage of energy storage capacitor is conducive to reduce the operating time of divide-shut brake, and less capacitance is conducive to reduce the speed that contact of breaker arrives the pass chalaza, therefore when less but the capacitor that initial voltage is higher of the elected amount of trying to please is as energy storage capacitor, more easily obtain close to desirable rate curve.This is because when the triggering signal conducting permanent-magnet manipulating mechanism coil of control unit output, can impel electric current fast rise in the coil because initial voltage is higher, makes electric current reach rapidly moving contact motion critical point, moves setting in motion unshakable in one's determination.Since need overcome moving contact resistance of motion acting and and the part of capacitor deposited energy is converted into the kinetic energy of moving contact, when the capacity of capacitor hour, the energy storage of electric capacity is less, and the voltage of capacitor is descended rapidly, thereby makes the coil current fast-descending.Because electric current descends, the electromagnetic force that coil produces reduces, thereby acceleration is reduced even oppositely, makes that to arrive the speed of closing chalaza controlled.The initial voltage of energy storage capacitor can not be too high, can determine according to the control reference voltage of control unit.According to mentioned above principle, choose near the one group energy storage capacitor of capacitance above-mentioned optional capacitance, and use the capacitance energy storage equivalence principle and determine corresponding capacitance voltage value.
To one of them circuit breaker in the type circuit breaker, respectively for each capacitor in selected one group of energy storage capacitor, control device is respectively sampling under open loop situations, namely in the situation from the feedback current of current sensor not, control device is sampled to circuit breaker and is obtained to comprise respectively a component combined floodgate dynamic characteristic of divide-shut brake coil current curve and contact displacement curve, step 702.
The divide-shut brake moving contact of breaker displacement curve that analysis obtains according to the desirable operating characteristics of aforesaid circuit breaker, is identified for obtaining capacitance and the magnitude of voltage of the type circuit breaker approximate ideal moving contact displacement curve, step 703.It should be noted that, capacitance when determined condenser capacity value can not be higher than normal breaking-closing operating, and magnitude of voltage must be lower than the magnitude of voltage of normal breaking-closing operating, thereby the capacitance energy storage when guaranteeing normal running can satisfy the needs of actual reclosing
Utilize described definite be used for obtaining reference current curve energy storage capacitor and initial voltage value, in the coil current curve of the circuit breaker of the actual use of the open loop situations down-sampling reference coil current curve as respective circuit breakers, step 704.
As mentioned above, because the impact of power supply and electromagnetic environment of living in comprises a large amount of noise jamming in the current signal of current sensor sensing.Preferably, the current signal of current sensor sensing is carried out 4 medium filterings of the windowing shown in equation 2, can obtain level and smooth current curve.In the process that the reference coil current curve is selected, selected current curve can be stored as the reference coil current curve after filtering.
The below is take the discrete control formula of three-phase circuit breaker as example, in conjunction with the control method of Fig. 8 specific descriptions according to breaker permanent magnet control mechanism of the present invention.
In the aforesaid permanent magnetic operating control device, when carrying out breaking-closing operating, trigger the IGBT conducting with closing coil, and start-up operation finishing testing mechanism, be operation timing mechanism in this example, is the breaking-closing operating restriction operating time, step 801.
Hall current sensor respectively the described output of sensing each phase coil current and each phase current signal of sensing fed back to described permanent magnetic operating control device, step 802.The Hall element that is independent of permanent-magnet operating mechanism for circuit breaker obtains to flow through the electric current of each phase coil of circuit breaker by the electric current of feed sensing control device IGBT output port output, and feeds back to the control unit of control device.Preferably, control unit is to carry out 4 medium filterings of windowing from the feedback signal of Hall current sensor, to eliminate the interference of various noises.
Reference current curve values corresponding to the current signal value of permanent magnetic operating control device sample-based and sampling instant calculated the triggering signal of actual IGBT, so that electric current and the reference coil current curve of each phase coil output are consistent step 803.Three-phase reference coil current curve can be each the phase current curve of coil according to the design of the operating characteristics of circuit breaker needs, also can be as above obtain in conjunction with the specifically described step of Fig. 7 each with reference to the coil current curve.
Realize the electric current of coil by reference current curve complete operation, can adopt based on the Current tracking PWM method of chain rate than mode that stagnate.In the present invention, wish that control device is with reference current curve output current, therefore with this reference current curve as command signal, from current sensor through the electric current of filtering as feedback signal, the switch by both instantaneous values relatively being exported each power device in the triggering signal control IGBT power stage unit controls power stage unit so that the output current of power stage unit and reference current curve be consistent.
Its algorithm principle is as follows:
Δ I=i
n-I
n Equation 3
I in the formula
nBe reference current value, i
nFor actual measurement and through the real-time current value after the filtering output, Δ I
MBe hysteresis band.Work as S
nBe 1 o'clock, connect power device, work as S
nBe at-1 o'clock, the rupturing duty device is to keep current state at 0 o'clock and do not carry out any action.Δ I
MValue directly related with control precision, Δ I
MWhen value was larger, the switch motion frequency was low, and tracking error increases; Δ I
MDuring the value smaller value, tracking error reduces, but the switch motion frequency is too high, may exceed the tolerance frequency scope during the power switch, and switching loss increases.Therefore, Δ I
MExtremely important.
Because this control method is that proportionality coefficient is 1 pure proportional controlling means in the automatically control, for measuring without lagging behind, willing system uses this algorithm can be controlled preferably effect.Yet, in actual applications, be subjected to the impact of hard ware measure and above-mentioned filtering; in the data of reality output with phase delay; and the inductance value of actual drive coil is larger, usually can exceed the ring width restriction when therefore using pure proportional control, is difficult to obtain desirable control effect.In order to obtain better control effect, proportional component and integral element in algorithm, have been introduced to obtain more desirable control effect.Its control algolithm is as follows:
K in the formula
P, K
D, K
IBe respectively proportionality coefficient, derivative compensation coefficient and integral coefficient, I
nBe reference current value, i
nFor actual measurement and through the real-time current value after the filtering output, Δ I is current deviation, Δ I
MBe hysteresis band, S
nDefinition identical with formula 4.Be different from general pid algorithm, differential term is as the linear compensation of measured value, rather than to the prediction of measurement data amount Error Growth trend in the formula 5.
By adopting according to control method of the present invention, the action situation of each divide-shut brake is consistent with corresponding action under the reference current curve, thereby makes the branch wire time of circuit breaker definite.Because all running statuses of the corresponding circuit breaker of reference current curve all are as can be known, circuit breaker can not occur causing coil current excessive because of switching overvoltage, cause further that moving contact speed is excessive and the collision that arrives is violent, bouncing even burning the situation such as coil occurs.The more important thing is, the time of each divide-shut brake of circuit breaker is determined, the divide-shut brake worst error time can be realized the specification requirement to the circuit breaker Synchronous Closing at ± 0.3ms.
Below with reference to instantiation effect of the present invention is described.
Example 1
This example specifies the method to set up of the control device reference coil current curve that is applicable to this circuit breaker take the 12kV vacuum circuit-breaker of the discrete control formula of three-phase as example.
At first, according to the parameter of vacuum circuit-breaker, choosing respectively capacitance is 2500 μ F, and the capacitance energy storage capacitor of 4700 μ F is used for control device and carries out the measurement of open-loop current curve.Fig. 9 is at the 210V initial voltage, and in the energy storage capacitor situation of 2500 μ F capacitances, when carrying out divide-shut brake control according to Open-loop Control Principles, the dynamic characteristic of circuit breaker comprises electric current, displacement and rate curve; Figure 10 is at the 170V initial voltage, the dynamic characteristic of circuit breaker in the capacitor situation of the energy storage of 4700 μ F capacitances.For conveniently checking, ordinate is the value after the sampled value of actual A/D is passed through scale operation, is not converted into actual value, and the chronomere of abscissa is ms.
As calculated, the maximal rate of two figure is about 1.2m/s.By actual measurement, the time of contact of dynamic/static contact shown in Figure 9, the time of contact of dynamic/static contact shown in Figure 10 was at the 18.626ms place at the 16.897ms place.Under 2500 μ F, because capacitance voltage is higher, electric current increases sharply before the moving motion unshakable in one's determination, and initial stage speed increases fast after the motion, closes the overall time and reduces thereby make to close.Yet because capacitance voltage descends rapidly, to last due in, electric current can't rise again, thereby the reliability that the pass is closed is difficult to guarantee, therefore pass through theory and interpretation, in this embodiment, select 4700 μ F, the current curve under the 170V is as the reference coil current curve of the control device according to the present invention.
Example 2
This example is used for checking based on drive coil current curve control method of the present invention, has wherein chosen the energy storage capacitor of 4700 μ F and has tested.It is 4700 μ F that Figure 11 and Figure 12 provide the energy storage capacitor capacitance, initial voltage voltage is respectively the coil current curve of the control device output under the 200V and the contrast of reference current current curve, and the contrast of displacement curve and the corresponding displacement curve of reference current curve.
Example 3
This example is used for checking based on drive coil current curve control method of the present invention, has wherein chosen the energy storage capacitor of 47000 μ F and has tested.It is 47000 μ F that Figure 13 and Figure 14 have provided capacitance, and voltage is respectively the coil current curve of the control device output under the 180V and the contrast of reference current current curve, and the contrast of displacement curve and the corresponding displacement curve of reference current curve.
Example 4
It is 47000 μ F that Figure 15 and Figure 16 have provided capacitance, and voltage is respectively the coil current curve of the control device output under the 200V and the contrast of reference current current curve, and the contrast of displacement curve and the corresponding displacement curve of reference current curve.
Can find out from above each example, under different operating voltage and different capacitances, coil current is always exported along the reference coil current curve.The dynamic error scope of actual output current and reference current error is less, remains in 8 measurement units, in control device of the present invention and control method, dynamic range is ± 0.3A in, satisfy the control needs to circuit breaker.Can find out from above-mentioned each curve, different with the control voltage of energy storage capacitor in the control device and capacitance, the PWM waveform of operating mechanism output changes thereupon.The PWM output frequency increases along with the increase of capacitance or initial voltage.Under high voltage, coil current always near reference current, super-high-current do not occur, has protected well coil.
Can find out from each displacement curve, in the operating process, the whole motion process displacement curve of moving contact almost overlaps with the corresponding displacement curve of reference current curve, therefore only need know the displacement data of reference current curve under each time value, just can know each contact displacement data constantly in the actual mechanical process, realize the non-cpntact measurement to contact.The monostable vacuum circuit-breaker separating brake that control method obtains according to the present invention and closing time error range are substantially in ± 0.3ms, and table 1 has provided the branch wire time under several groups of different situations that actual measurement obtains.
Branch wire time under table 1 different situations
Consider in actual measurement experiment, the vibration of circuit breaker may have influence on actual measurement to the displacement measurement time, thus the actual pass time of closing of circuit breaker should be better than the dynamic range of above-mentioned measurement, reached good control effect.Effectively guaranteed by this method the stability of the operating time of circuit breaker; owing to using higher operating voltage; and rationally control drive current, and protected coil, it can not burnt because of overcurrent; when having accelerated branch wire time; rationally control divide-shut brake speed, well protected moving contact, avoided it because of the distortion that may cause by excessive impulsive force, spring etc.; increase the service life, also improved the reliability of operation.
Example 5
It is 47000 μ F that Figure 17 and Figure 18 have provided capacitance, and initial voltage is the coil current curve of lower three discretes control of 180V 12kV vacuum circuit-breaker in closing position combined floodgate and open position separating brake situation.Can find out from Figure 17 and Figure 18, the electric current of coil has obtained good control when closing position combined floodgate and open position separating brake, and its current curve overlaps with reference curve trend substantially, does not have the overcurrent phenomenon, and drive coil has obtained effective protection.
Because capacitance energy storage needs should be able to finish separating brake-combined floodgate at least, and the O-CO action is namely finished in the action of separating brake, can export by reference curve for making the control curve in actual applications, should choose capacitance should be far above 4700 μ F, and the electric capacity initial voltage should be greater than 170V.Experiment confirm uses rated voltage 250V, when capacity is the electric capacity of 47000 μ F, in the situation that charging voltage is 210V, at least can finish the O-CO-CO operation by reference curve, the displacement curve of each reclosing and 4700 μ F, the displacement curve of 170V overlaps, finish above-mentioned action after its electric capacity overbottom pressure still greater than 170V, satisfy the actual guarantor's needs that continue fully.Obviously higher charging voltage or larger capacitance can further improve the reclosing number of times during actual the use, better finish the relaying protection action thereby be conducive to circuit breaker, promote stability of power system.
According to the motion state that can effectively control moving contact of breaker based on the control method of permanent magnet mechanism dynamic characteristic of the present invention.Because coil current is controlled in the breaker operator process, avoid appearing at close a floodgate under higher operation voltage and the "on" position and gate-dividing state under during separating brake, the overcurrent phenomenon of coil has well been protected coil.By improving the capacity that is used for obtaining the capacitance voltage of reference curve and reduces electric capacity, can effectively shorten the speed that chalaza is closed in operating time and control, reduce collision to the impact of contact, reduce the contact bounce phenomenon, the useful life of extending mechanism.Because reduced the loss of collision energy, under the same conditions, circuit breaker reclosing number of times is improved.
The time of each divide-shut brake of circuit breaker is determined, the divide-shut brake worst error time is at ± 0.3ms, and much smaller than the requirement of Synchronous Closing Technology index, namely the separating brake error time is at ± 2ms, and the combined floodgate error time is at ± 1ms.Therefore can satisfy the working control demand according to control method of the present invention.
Should be appreciated that abovely to have been described in detail by the preferred embodiments of the present invention technical scheme of the present invention, should be appreciated that above explanation is illustrative and not restrictive.Those of ordinary skill in the art is reading on the basis of specification of the present invention and can make amendment to the technical scheme that each embodiment puts down in writing, and perhaps part technical characterictic wherein is equal to replacement; And these modifications or replacement do not make the essence of appropriate technical solution break away from the spirit and scope of various embodiments of the present invention technical scheme.Protection scope of the present invention is only limited by the claims of enclosing.
Claims (7)
1. the control method of a permanent magnetic vacuum breaker, the method comprises the coil current of measuring permanent magnet mechanism, obtains for the real-time reference current curve of control, and the ring control algolithm that stagnates,
It is characterized in that need not increasing any parts at breaker body, electric current by real-time measuring coil and with the contrast of reference current, determined the actual triggering signal of power device by the ring control algolithm that stagnates, realization is to the real-time closed-loop control of coil current, thereby the branch wire time of permanent magnetic vacuum breaker is consistent
The method further comprises:
Be used for obtaining the method for reference current curve,
4 medium filterings of windowing that are used for the signal Real-Time Filtering,
Follow-on stagnant ring control algolithm.
2. vacuum circuit-breaker control method as claimed in claim 1 is characterized in that, the method comprises 4 medium filterings with the rectangular window translation, is used for the real-time sampling current signal is carried out filtering, to satisfy real-time control algolithm to the requirement of input signal.
3. vacuum circuit-breaker control method as claimed in claim 1, it is characterized in that using modified hysteresis control method thereof calculates real-time current value and reference current value difference, and further convert the pwm signal of driving power device to, realize the tracking control to coil current.
4. vacuum circuit-breaker control method as claimed in claim 1 is characterized in that, the acquisition methods of Coilreference current curve, and the method includes the steps of:
A. be identified for obtaining capacitance and the magnitude of voltage of reference curve, for the circuit breaker of same model, this step only need be carried out once, wherein comprises following content:
Determine that according to the parameter of known circuit breaker model normal execution is once closed a floodgate or capability value and the initial voltage of the minimum energy storage capacitor that separating brake is required;
B. before a certain circuit breaker of described model comes into operation, the capacitance and the magnitude of voltage that utilize A to determine, under open loop situations, carry out respectively separating brake and closing operation, by control device self sampling and record the divide-shut brake current curve of this operation as the reference curve of the normal separating brake of this circuit breaker and closing operation.
5. vacuum circuit-breaker control method as claimed in claim 4, it is characterized in that, choose the capacitance when being greater than or equal to determined capacitance be used to obtaining reference curve as normal breaking-closing operating, and choose the magnitude of voltage that is higher than be used to the normal breaking-closing operating of magnitude of voltage conduct that obtains reference curve, the capacitance energy storage during with the assurance normal running satisfies the needs of reclosing.
6. vacuum circuit-breaker control method as claimed in claim 4 is characterized in that, describedly is identified for obtaining the capacitance of reference curve and the step of magnitude of voltage further comprises:
Use the principle of capacitance energy storage equivalent, the capacitance energy storage formula
Improve the voltage of electric capacity and reduce the capacity of electric capacity, so as when to reduce the whole time of divide-shut brake the end speed of restriction divide-shut brake,
Under the open loop state of a control, change capacitance and voltage and repeatedly test to obtain best vacuum circuit-breaker displacement curve, be identified for obtaining capacitance and the electric capacity initial voltage value of this model circuit breaker reference current curve, this step is used for optimizing reference curve.
7. the control device of a permanent magnetic vacuum breaker, the described Method And Principle design of this application of installation claim 1, it comprises the capacitor charging/discharging control unit, IGBT power stage unit, current measuring unit, and control core unit is characterized in that,
This capacitor charging/discharging control unit is used for according to the signal that discharges and recharges from the control core unit energy storage capacitor of control device being discharged and recharged,
This IGBT power stage unit is used for according to exporting the discharging current of energy storage capacitor to coil from the triggering signal of control core unit,
This current measuring unit is measured the coil current of described IGBT power stage unit output and is fed back to the control core unit,
This control core unit is based on the coil current of measuring and the contrast of reference current, utilize follow-on stagnant ring control algolithm to be identified for the triggering signal of IGBT power stage unit, make the coil output current consistent with predetermined current, thereby the branch wire time of permanent magnetic vacuum breaker is consistent.
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| CN117438241A (en) * | 2023-12-15 | 2024-01-23 | 霍立克电气有限公司 | Switching-on control method of vacuum circuit breaker |
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